Evidence that monoamines influence human evoked potentials

Schafer, Edward W. P.; McKean, Charles M.

doi:10.1016/0006-8993(75)90607-1

Cited by 55 publications

(21 citation statements)

References 21 publications

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“…Abnormalities in 5-hydroxytryptamine have long been associated with migraine, and in phenylketonuria, which causes reduced brain concentrations of catecholamines and 5-hydroxytryptamine, PRVEP latency is prolonged, but can be normalised by dietary phenylalanine restriction 27. However in this condition P100 amplitudes are reduced 28…”

Section: Discussionmentioning

confidence: 99%

Long term decline of P100 amplitude in migraine with aura

Khalil

Legg²,

Anderson³

2000

Journal of Neurology, Neurosurgery &Amp; Psychiatry

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Objectives-To investigate visual function in migraine using visual evoked potentials. Methods-Electroretinograms(ERGs) and visual evoked potentials (VEPs) to single flash (SF) and pattern reversal (PR) stimuli were studied in 92 migraine subjects and 62 controls. Results-In subjects with migraine, ERGs to single flash were normal. Mean latencies of the P1 and P2 waves in the SFVEP were increased at the occiput by 6% and 4% respectively, but normal at the vertex. Mean latency of the P100 wave in the PRVEP was increased by 5%. These increases were not related to the presence or absence of an aura or to the duration of migraine. P100 amplitude showed a more complex abnormality. It was increased in migraine without aura by 23% compared with controls, regardless of duration of migraine. In migraine with aura it was similarly increased, by 23%, in cases of short duration, but in addition it showed a sharp decline with duration. In cases with a duration of 30 or more years it was 36% less than in cases of short duration, and 21% less than in controls. Conclusions-Subjects with migraine have constitutionally prolonged VEP latencies and increased P100 amplitude, but the latter declines to below normal in cases with a long history of migraine with aura. This decline may reflect subtle neuronal damage within the visual system from repeated transient ischaemia experienced during the aura. Future electrophysiological and other studies will need to be controlled for duration of migraine history. The studies reported here formed part of a PhD project 4 in which visual function was studied in 92 subjects with migraine and 62 controls, by neurophysiological and psychophysical methods. Here we report the results of investigation by electroretinogram (ERG), SFVEP, and PRVEP. Some preliminary data have already been published. Methods SUBJECTSThe patients in this study were not a random sample of the migraine population. They came from a wide age range, and there was a deliberate selection for those with a visual aura and with attacks precipitated by visual stimuli, to provide subgroups large enough for meaningful comparisons. Controls were found among colleagues, the spouses, or friends of subjects with migraine, and other volunteers. All subjects had a visual acuity of 6/6 or better, and none of them had any visual disorder.All 92 subjects fulfilled the International Headache Society (IHS) criteria for a diagnosis of migraine with or without aura.7 There were 72 women and 20 men, aged 16-59 years (mean 40.2 (SD 12.5) years). All were free of headache at the time of testing, and none were taking prophylactic treatment. Forty seven had migraine with aura (MA), 37 had migraine without aura (MO), and eight had both. Results from these eight patients have been included only when the whole migraine group is considered. All patients with MA had a visual aura, and seven also had other aura symptoms. Seventy three patients reported attacks triggered by visual stimuli, such as bright lights, flashing lights, or patterns. Migraine ...

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Section: Discussionmentioning

confidence: 99%

Long term decline of P100 amplitude in migraine with aura

Khalil

Legg²,

Anderson³

2000

Journal of Neurology, Neurosurgery &Amp; Psychiatry

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“…BAEPs showed a slight but significant prolongation of central conduction time. The divergent results of flash and pattern VEPs may be due to different types of epilepsy and different cerebral processing of flash and pattern VEPs (Schafer and McKean, 1975; Berdjis and Demisch, 1985). Halliday and Halliday (1980) studied flash-induced occipital VEPs in 17 patients with PME.…”

Section: Discussionmentioning

confidence: 99%

“…Dopaminergic dysfunction in Baltic PME may not be directly related to the etiology of the syndrome, as L-dopa treatment did not result in significant clinical improvement as demonstrated by Leino (1981). Normal electroretinogram findings in the presence of prolonged VEP latencies in dopaminergic dysfunction states (Schafer and McKean, 1975) suggest that the defects are central from the retina. It may be at the retina, at the level of lateral geniculate bodies, or it may be an intracortical defect (Obeso et al, 1985).…”

Section: Discussionmentioning

confidence: 99%

Visual Evoked Potentials, Brainstem Auditory Evoked Potentials, and Quantitative EEG in Baltic Progressive Myoclonus Epilepsy

et al. 1986

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Visual and brainstem auditory evoked potentials (VEP and BAEP, respectively) and quantitative EEG were studied in 16 patients with Baltic progressive myoclonus epilepsy (PME). The study demonstrated significantly delayed VEP latencies but normal amplitudes in Baltic PME. BAEPs showed slight but significant prolongation in central conduction time. Quantitative EEG revealed diminution of beta and alpha activity and accentuation of theta and delta activity. The slowing in VEP latencies is suggested to be due to impaired synaptic transmission and to reflect dopaminergic dysfunction in Baltic PME. We conclude that there is a multimodal disturbance in sensory projections to cortical areas in Baltic PME. The results give further evidence that nondemyelinating disorders--but with synaptic transmission defects--can produce changes in evoked potentials. The changes in epileptic brain are not confined to hyperexcitable epileptic neurons, but more widespread electrophysiological phenomena are produced.

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“…For instance, the third positive peak (P3) is a late cognitive potential that has a larger amplitude if a stimulus is infrequent and task-relevant (for review, see (8)). ERPs have excellent temporal resolution; changes have been found in the early peaks of scalp-recorded potentials of children and adults with PKU (9)(10)(11)(12)(13)(14)(15)(16). PKU may also affect cognitive P3, as recent studies have shown that dopamine monotherapy in Parkinson's disease causes a reduction in P3 latency (17) for an auditory task.…”

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confidence: 99%

Visual event‐related potentials in children with phenylketonuria

et al. 2000

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Visual event-related potentials (ERPs) were examined in 16 children (aged 5-14 y) with phenylketonuria (PKU) and 16 age-and sex-matched controls. Lifetime median measures of phenylalanine (Phe) were 230-460 mmol/l. The most recent Phe levels were 56-624 mmol/l. ERPs were recorded whilst the children performed a discrimination task. All stimuli were square wave gratings degree, which appeared for 33 ms. A response to an infrequent grating that differed in orientation or spatial frequency was required. The older children with PKU had a delay in the first peak (P1) of the ERP, and age-related changes in the amplitude of P1. There was attenuation of the second peak across age groups in PKU. There was no evidence of reduced response accuracy or longer reaction times in children with PKU. Latencies of the cognitive P3 were not delayed in PKU. The delayed early peaks are consistent with previous studies that have shown delayed visual evoked potentials in PKU. The lack of differences in reaction time and P3 may be due to relatively good Phe control in children with PKU, or to the simplicity of the task. Suggestions are made for future ERP studies of PKU. phenylalanine, phenylketonuria, reaction time, P3, visual evoked potentials

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Evidence that monoamines influence human evoked potentials

Cited by 55 publications

References 21 publications

Long term decline of P100 amplitude in migraine with aura

Long term decline of P100 amplitude in migraine with aura

Visual Evoked Potentials, Brainstem Auditory Evoked Potentials, and Quantitative EEG in Baltic Progressive Myoclonus Epilepsy

Visual event‐related potentials in children with phenylketonuria

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